It depends on what several things: PCA or SCCA, as they are slightly different. Street Stock (SS), Stock (S) or Production/Improved? And finally how much do you want to spend???? For our 2.0l 1974 we bought a used set of EMPI 4-bolt rims with shaved Yoko A008Rs (like new) for $300. They are 205x50x15 and are smaller in diameter than the street tires so we have a little lower gear and so far neither my daughter or I have reached their traction limits yet( well maybe braking). If you are just starting and don't have lots of $$$$, I'd try to stay near stock width so they don't rub and increase the cost of the fun!